Acta Musei Moraviae

Petrography and mineralogy of a soapstone body at the locality Bischofsgraben near Sobotín (Hrubý Jeseník Mts.)

The Sobotín Massif is mainly composed of amphibolite and amphibole gneisses and less of greenschists, metahornbledites and sporadically serpentinites. Soapstone bodies are characteristic for the Sobotín Massif. Soapstone used to be extracted from the Smrčina quarry (near Sobotín) and the Zadní Hutisko quarry (near Vernířovice) that are known as mineralogically important localities nowaday. The aim of the paper is petrographical and mineralogical description of a little soapstone body exposed in central part of the Sobotín Massif at Bischofsgraben locality. Structure of the body shows remarkable symetrical zonality. Three major zones can be distinguished in direction from the center to the margin of the body: falc schist – actinolite schist – chlorite schist. There are transition zones among mentioned rock types. Typical soapstone (talc + dolomite) occuring at Smrčina and Zadní Hutisko localities has not been discovered at Bischofsgraben locality. Soapstone is apparently part of this body but it has not been observed in situ. Chromite is abundant accessory mineral of the soapstone body. Studied soapstone body probably developer as a result of hydrothermal alteration of hornblendite (metahornblendite).